Henry matthew wells



UNITED STATES PATENT OFFICE.

HENRY MATTHEW WELLS, OF SI. ES-ON-SEA, NEAR BLACKPOOL, AND JAMES EDWARD SOUTHCOMBE, OF BIRKENHEAD, ENGLAND.

LUBRICATING-OIL.

No Drawing.

T 0 all whom it may concern Be it known that we, HENRY MATTHEW WELLS and JAMES EDWARD SoU'rHcoMBn, subjects of the King of Great Britain, residing, respectively, at St. Annes-on-Sea, near Blackpool, in the county of Lancaster, and Birkenhead, in the county of'Chester, both in the Kingdom of England, have invented certain new and useful Improvements in Lubricating-Oils, of which the following is a specification.

This invention relates to improvements 1n lubricating oils. It as long been recognized that for many purposes mineral hydrocarbon oils do not lubricate so well as animal or vegetable saponifiable oils and fats and accordingly compounded lubricating oils have been largely used, which consist of mixtures of mineral oils with saponifiable oils and fats...

\Ve have discovered that the active prin- ('iple which enables such saponifiable oils to improve the lubricating properties of mineral oils is a'relatively small quantity of free fatty acid, either preexisting in the saponifiable oil, or formed therefrom by hydrolysis during lubrication. Our invention therefore consists primarily in replacing a relatively large amount of saponifiable oil or fat by a relatively minute amount of a suitable free fatty or other organic acid.

It will be seen that the principle underlying our invention is in direct opposition to prevailing views, and it will be desirable therefore to explain the rationale of the process.

Hitherto it has been consideredthat free fatty acid is a constituent to be rigorously 4 excluded from a lubricating oil, on account of the fear of corrosion. We approached this problem by making a study of the-capillary properties of various oils, using the drop pipette to measure the interfacial ten- The first result of our work was to show that the saponifiable oils or compounded oils showed a' low interfacial tension against water. We next demonstrated that this low interfacial tension was due to the presence of small quantities of free fatty acids, and concluded that the'eflicacy of the sap'onifiable oils depended on their free acid content and that in fact these oils merely acted as carriers of free acid.

Specification of Letters Patent. Patented Oct, 21, 1919,

Application filed March 19, 1918. Serial No. 223,378.

alone to amineral oil and discovered that the lubricating. properties were greatly improved while the interfacial tension against water was correspondingly lowered.

Our invention presents three great advantages over existing practice (1) By isolating the active principle we a are enabled to produce oils of widely varying properties as will be described hereafter.

(2) We are enabled to replace a large amount of saponifiable oil or fats in a compounded lubricant by a small amount of free fatty or organic acid and thus obtain abetter product at a much less cost. The saving in saponifiable oil is especially important since we can prepare valuable products while liberating large quantities of saponifiable oils for use as foods.

(3) In actual practice we find that far from increasing the danger of corrosion we are enabled to minimize it.

In our products the amount of fatty acid is small and limited; whereas in the usual commercial products, the amount may be small initially but it is potentially very large. Owing to hydrolysis during lubrication the percentage of fatty acid in a compounded oil containing say ten per cent. of saponifiable oil is potentially equal to a very large fraction of this ten per cent. The danger from corrosion is large and uncontrollable. impossible to avoid corrosion completely by employing lubricating oils containing (initially) the minimum quantity of free fatty acid. Our experiments show that on the contrary a small quantity of free fatty acid is It is this factor which made it be added as such, so that its amount is limited and cannot increase, whereas if the free acid is present as the impurity or hydrolytic product of a saponifiable oil, its amount can increase very largely.

The free acid, preferably free fatty acid, e. 9., commercial olein containmg' 95% free acid, and or whale oil-fatty acids either hardened or not may be added in quantitles of 1 to 2% to the mineral oil, or the free fatty acid may be incorporated with a small quantity of mineral oil, and this active mixture may be diluted with mineral oil as required. Many of the advantages of the mvention may be obtained by mcorporatm the free fatty acid with a smallquantity of 11 a saponifiable oil as vehicle but it is desirable to employ mineral oil for this purpose.

The choice of the free acid is dependent on the lubricating and other properties de- 5 sired. Broadly speaking, the best free organic acid to use is that which is obtained from the fatty oil whose properties it is desirable to reproduce. Thus rape oil and cocoanut oil impart different properties to the compounded oils made therefrom and these properties may also be imparted by adding small quantities of the free fatty acids corresponding thereto.

In theory the process depends on the principle that lubrication is a function of the capillary properties of the oil. A satisfactory lubricant must wet the bearing surfaces so that a thin film of lubricant will tend to move into the constricted areas of great pressure. Now in practice the bean ing surfaces are usually contaminated with a film of moisture and there is a liability to form oxid films. The action of the free acid is to 'lower the interfacial tension between oil and water and the mechanism of the process is apparently to allow the oil to displace the water film from the bearing surface. The chemical afiinity between the acid and the metallic surface or the oxid film (if present) runs parallel with a similar reduction in interfacial tension which has similar results.

The action of the free fatty or other acid depends on its molecular weight. If any acid of very low molecular weight Such as butyric acid is used it will exert a deemulsifying efi'ect and we can therefore apply our process to produce non-emulsifiable mineral oils. This is of great im ortanee in certain classes of work where t e oil is violently ag1tated with water and much trouble is experienced through emulsification. On account of the low molecular weight, these acids are much more active and it is not desirable to exceed the limit of 1%.

On the contrary certain fatty acids of high molecular weight possess the property of mcreasing the emulsibility of hydrocarbon oils which is of importance in certain cases of lubrication. Th'us certain highly unsaturated acids of hi h molecular weight are especiall active. This'i's probably associated wit the phenomena of polymerization and soap formation. I

Our invention is thus based on adding to a mineral oil a relatively minute amount of a compound which lowers theinterfacial tension between the oil and water in the manner described. 1 v

60 Anyhydrocarbon oil ma beu'md, e. 9., from; petroleum, coal tar, s ale, colophony,

Fatty acids. are very suitable additions;

the commercial products are satisfactory. They maybe obtained from any class of emma "tured from raw petroleum, shale, coal-tar or colophony.

The invention may be applied to improve the lubricating properties also the emulsifying and or the deemulsifying properties of mineral oils.

We shall now give examples showin the application of our invention but it w l' he understood that these are merely illustrative.

E's/"ample I.

. Emample I1.

A concentrated compound is prepared. containing equal weights of commercial -fatty acids and mineral oil by warming and mixing these ingredients. This concentrated compound is added to a hydrocarbon oil to the extent of 3% byweight (=1% fatty acid).

7 Example HI.

A non-emulsifying oil is prepared by adding 0.8% of butyric,- cinnamic or an oilsoluble' sulfonic acid to hydrocarbon oil. Certain naphthenic acids also exert this deemulsifying efiect.

Ewample IV.

An emulsifying oil suitable for marine lubrication or thelike'is produced by adding 1% of the acids obtained from rape oil or wool-grease and the like to a viscous hydro carbon oil.

The product closely resembles a compounded oil made from hydrocarbon'oiland blown rape oil. e 110 Ewample V.

A mineral oil of high viscosit is treated with 2% of the commercial aci from castor oil or even with 2% of olein. The pro- 15 duct is similar in roperties to castor oil at I relatively not too i h temperatures, and is very suitable for liirication of aeroplane en es. a e declare that what we claim is 1. A lubricating oil consisting of a hydrocarbon oil containing a relatively minute amount of a substance which lowers the surface tension of said oil ainst water with- .out admixture of more t an a correspondin ly minute amount of saponifiable glycer1 2. A lubricating oil consisting of a hydro carbon oil contammg a relatively minute amount of a free organic acid, without more thana substantially equal amount of saponiaddition of more than a correspondingly .fiable glycerid.

relatively small amount of castor oil. 3L A lubricating oil consisting of a hydro- 7. The process of'prep'arin a compound. carbon oil contalning a relatlvely minute lubricating oil from hydrocarbon oil, which 25 amount of a free fatty acid unaccompanied consists in admixing a free fatty acid with by more than a correspondingly minute a substantially equal amount of hydrocarbon amount of saponifiable glycerid. oil and adding a predetermined amount of LA. lubricating oil consisting of a hydrosaid mixture to the oil to be compounded. carbon oil containing about one to two per- 8. A hydrocarbon oil containing a viscous 3 cent. of free fatty aclds. mineral oil and approximately two per cent.

5. A lubricating oil to replace a compound of fatty acids derived from castor oil.

"lubricating oil consisting of a hydrocarbon In Wltness whereof, we have hereunto oil plus a relatively large amount of a sasigned our names this. 1st. day of March, ponifiable glycerid, characterized by the re 191 8, in the presence of two subscribing wit- 5 placement of said .glycerid by a relatively messes. minute amount of the corresponding fatty I acid derived from said glycerid. HENRY MATTHEW WELLS" 6. A lubricating oil consisting of a min- JAMES EDWARD BOUTEOOMBE' eral oil highly viscous at atmospheric tem- Witnesses:

peratures, containing a small uantity of Y HAROLD EDWIN Porrs, commercial fatty acid substantially without RI HARD WHIMSTER ELANDJ 

